Study On The Influence Of Rebar Corrosion On Mechanical Performance Of Heavy-Duty Railway Piers And Treatment Measures

With the booming development of the railway transportation industry,heavy-haul railway transportation brings huge benefits to the transportation industry due to its large capacity and high efficiency.But it also has an adverse effect on railway piers,for example the vertical and vertical loads gradually increase and the lateral vibration response increases.The railway bridge piers have reduced mechanical properties due to salt and alkali corrosion,and the lateral vibration response is further aggravated,which may affect the safe operation of trains.In this paper,the main research direction is to study the influence and prevention measures of saline-alkali corrosion on the heavy-duty railway piers.The main research contents and conclusions are as follows:(1)The principle of salt and alkali corrosion on piers and the factors affecting the corrosion rate were analyzed.Through the analysis shows that: The erosion of chloride salt leads to the corrosion of the steel bars inside the pier,Sulfate and alkali erosion cause deterioration of the pier concrete,which may affect the safe operation of the train;Due to the increase in axle load and annual traffic,heavy-load transportation can lead to accelerated corrosion rate of bridge piers.(2)The influence of corrosion of steel bars caused by chloride corrosion on the mechanical properties of cylindrical piers was studied.The analysis showed that: In the range of 0% to 14% of the corrosion rate of the steel bar,the thickness of the protective layer of the pier body is gradually reduced as the corrosion rate of the steel bar increases,and the stress of the section of the pier body increases,and the stiffness decreases;After the corrosion rate of steel bars exceeds 14%,the stress and stiffness of the pier sections are almost constant.(3)Based on the engineering background of the No.1 bridge across the Shekang Highway in the Shuo-Huang Railway,a finite element model was established to study the influence of steel corrosion on the natural frequency and lateral amplitude of the bridge piers.Through analysis shows: With the increase of corrosion rate of steel bars,the natural vibration frequency of the pier body gradually decreased,and the lateral amplitude of the pier top increased.The natural vibration frequency of piers decreased by the maximum 9.39% and the lateral amplitude of piers increased by 25.5%;Under the action of heavy-duty trains,the lateral amplitude of pier tops further increases,and the lateral amplitude of the top of piers of trains with 21 t axle load increases by 25% compared with the axle load of 27 t;The reliability of the theoretical analysis method is verified by comparing the measured data of the lateral peak amplitude with the simulated data.(4)This paper analyze the prevention measures and reinforcement measures adopted by bridge piers under different rebar corrosion conditions,and simulate and analyze the reinforcement effect of No.1 bridge across Shigang Highway of Shuohuang Railway.